class_docstr: test GridspecLayout
code: def test_setitem_slices(self):
      box = widgets.GridspecLayout(2, 3)
      button1 = widgets.Button()
  
      box[:2, 0] = button1
      assert len(box.children) == 1
      assert button1 in box.children
      button1_label = button1.layout.grid_area
  
      assert (
          box.layout.grid_template_areas
          == '''"{b1} . ."\n"{b1} . ."'''.format(b1=button1_label)
      )
  
      box = widgets.GridspecLayout(2, 3)
      button1 = widgets.Button()
      button2 = widgets.Button()
  
      box[:2, 1:] = button1
      assert len(box.children) == 1
      assert button1 in box.children
      button1_label = button1.layout.grid_area
  
      assert (
          box.layout.grid_template_areas
          == '''". {b1} {b1}"\n". {b1} {b1}"'''.format(b1=button1_label)
      )
  
      # replace button
      box[:2, 1:] = button2
      assert len(box.children) == 1
      assert button2 in box.children
      button2_label = button2.layout.grid_area
  
      assert (
          box.layout.grid_template_areas
          == '''". {b1} {b1}"\n". {b1} {b1}"'''.format(b1=button2_label)
      )
  
imports: from unittest import TestCase
  import pytest
  import traitlets
  import ipywidgets
  from ipywidgets.widgets.widget_templates import LayoutProperties
label_desc: Use image node_id 3 for calling the TestGridspecLayout obj's underlying member method code with example usage: obj.test_setitem_slices() without return types